Pearl ~ They give purity and promote faith, charity, and integrity, truth and loyalty. Pearls are one of our most ancient gems with records of commercial harvesting going back 2500 years. Their natural occurrence is very rare, with only one in several million shellfish ever producing a pearl. Oysters are the best-known source, but clams, mussels, and abalone also produce pearls. (Biwa grown freash water pearl)